Quote Originally Posted by douglas View Post
That principle only applies if the two sources actually contradict each other. Unless the Monster Manual states that non-humanoids with 1 hit die cannot trade it for a class level, rather than being silent on the matter, the DMG rule is valid.
I don't see your logic there. This would also mean that if you describe a PC (of any race) with a "monster" Rogue entry including a set of hide armor, it's automatically proficient with all Medium armor (Monster Manual, page 5) because the Player's Handbook is silent on the matter (i.e., doesn't say Rogues are not proficient with Medium armor). If you take rules outside the scope wherein which they are defined you'll get unintended consequences.

Also the Monster Manual isn't exactly "silent on the matter" of non-Humanoids and class levels. That exchange is specified under the Humanoids and Class Levels topic (Monster Manual, page 290), the Humanoid type entry in CHAPTER 5: MAKING MONSTERS, and the Humanoid Type Glossary entry (page 310). All references to the 1 HD exchange are specific to Humanoid creatures. The details for all other creature types, in both Chapter 5 and the Glossary (28 total references), lack any mention of an exchange option. Thus assuming the DMG is correct here means assuming the Monster Manual was incorrect in restricting the scope of this exchange by titling the rule Humanoids and Class Levels and then omitting necessary rules text in those 28 other places (if they were going to specify that exchange redundantly for each creature type).


Short version: the DMG text necessarily contradicts the MM rule labeled Humanoids and Class Levels if it states that that rule isn't specific to Humanoids. This disagreement is resolved with the MM being correct.